diff --git a/.changeset/five-oranges-melt.md b/.changeset/five-oranges-melt.md
new file mode 100644
index 000000000000..26507d3a487b
--- /dev/null
+++ b/.changeset/five-oranges-melt.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-cloudflare-workers': patch
+---
+
+revert change to Cloudflare ES target version
diff --git a/packages/adapter-cloudflare-workers/index.js b/packages/adapter-cloudflare-workers/index.js
index ef18d54d1e23..e47af92ff445 100644
--- a/packages/adapter-cloudflare-workers/index.js
+++ b/packages/adapter-cloudflare-workers/index.js
@@ -55,7 +55,7 @@ export default function () {
 				entryPoints: [`${tmp}/entry.js`],
 				outfile: `${entrypoint}/index.js`,
 				bundle: true,
-				target: 'es2019',
+				target: 'es2020',
 				platform: 'browser'
 			});